MD Anderson Cancer Center



[ Music ]Lisa Garvin: Welcome to Cancer Newsline, the podcast series from the University of Texas MD Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research and diagnosis, treatment and prevention, providing the latest information on reducing your family's cancer risk. I'm your host, Lisa Garvin, and today we have two guests. They're both from our Department of Neuro-Oncology here at MD Anderson. Assistant professors Dr. Ivo Tremont and Karin Woodman. Welcome to you both. Thank you for coming and being with us today.Dr. Karin Woodman:Thank you for having us.Lisa Garvin: And what we're going to talk about today is some sort of the neurological problems that can crop up with cancer treatment. , you know, some chemotherapies are still very toxic but effective. And it seems like nerves can get affected pretty regularly with certain treatments, correct Dr. Woodman?Dr. Karin Woodman: Yes. So peripheral neuropathy is seen about 5 to 10%, in the general population. In our cancer population, it's higher because of some of the chemotherapies that we use. So the three big classes of chemotherapies that can cause peripheral neuropathy include the platinum agents, so cisplatin being the major offender. The taxanes, so Taxol being the first drug that's heavily associated. And the vinca alkaloids, so vincristine being the main component of that.Lisa Garvin: And tell me what is neuropathy? I think a lot of people know, especially diabetics who have to deal with this on a regular basis, but what are the common symptoms of peripheral neuropathy? And what is exactly the physiological thing going on?Dr. Karin Woodman: Yes. So there's a wide range of symptoms. But very commonly patients might experience sensory symptoms first and that ranges from a lack of normal sensation, what we call numbness. To having abnormal additional sensations, such as tingling, pins and needles, burning, lightning or electrical sensation. And so you have the absence of normal sensation and then additional abnormal sensations. You can have pain, what we call neuropathic pain, which is of a burning or electrical nature. And then you can have weakness. So motor weakness because the motor nerves that go to muscles can also be affected.Lisa Garvin: Have you found that there's any particular demographic that's affected more than others or is it kind of sporadic in nature?Dr. Karin Woodman: Yes. So good question, you know, because diabetes is the most common cause of peripheral neuropathy in North America. We have a lot of diabetics, who are cancer patients, and so they're already coming with one vulnerability to developing peripheral neuropathy. And then they have a neurotoxic chemotherapy. And so they tend to be affected more heavily and also more frequently than a patient without diabetes.Lisa Garvin: Is this something that you warn patients when they're on particular chemotherapeutic regiments to say hey, this is a possible side effect and you should watch for it?Dr. Karin Woodman: Yes. I'm sure the patients are warned by their primary oncologist. When they come to see me, they tend to be either someone that has particularly troublesome symptoms of peripheral neuropathy that's not manageable by the primary oncologist. Or they've developed the peripheral neuropathy. And they need further workup to find additional causes of the neuropathy because something's a little bit atypical about their case.Lisa Garvin: And Dr. Tremont, how do you work therapy for these kinds of disorders into regular cancer treatment? Is it a simultaneous thing? Or how do you manage this along with cancer treatment?Dr. Ivo Tremont: Right. What happens is that we haven't found or there is no available specific treatment that will be effective at preventing or tackling the problem in the background. What we do have is medication that can relieve the symptoms. So we do symptomatic treatment. And that can go along with the therapies or the systemic chemotherapy the patient is receiving. Now there has to be a conscientious decision by the patient knowing that, if we're going to initiate therapy or the treatment, these drugs can cause also adverse effects. And many of the therapies we do -- we recommend to relieve or they're known to be effective. For example, relieving pain, neuropathic pain, are agents that can cause, for example, cloudiness. Or the patients can get a little bit confused or drowsy initially. Some of them get used to the treatment, and they can tolerate it. Others don't. So this is something that we need to discuss with patients. And I'm sure that Karin does it too with her patients, but it's a major concern for them.Lisa Garvin: And is -- neuropathy can tend to be -- it can either be temporary or permanent, is that correct?Dr. Karin Woodman: Yes. So we give the general figure that about a third of patients will have complete resolution of their peripheral neuropathy symptoms. If it's due to the chemotherapy, once they've completed treatment. Usually within a few months they'll resolve. About a third of patients have some residual symptoms that have improved from the worst point. And then about a third are left with residual symptoms that are pretty similar to when they first developed the symptoms. But for the most part, most patients do get better.Lisa Garvin: And how do you manage patient expectations because I'm sure that some patients I already got cancer. Now I got tingly feet too. I mean how do you handle that?Dr. Karin Woodman: Yes. Well it's important to keep perspective. The focus of the primary oncologist is to kill the cancer, get rid of it. And so some side effects are acceptable when the goal is to eradicate cancer. I think that we try to maximize quality of life. So treating, focusing the treatment on pain, on disability. So that patients can walk better. Have good balance. They can function in their daily lives at work, at home, should be the goal. And if they have a little bit of numbness that's residual, a little bit of tingling but not quite pain. You know that's acceptable for most patients but everybody's different.Lisa Garvin: And you said there were different -- of course, neuropathy is the most common because we do see it in the general population. But you say there are other pathies or neurological disorders that might arise from cancer or its treatment.Dr. Karin Woodman: Yes. And that's where the fun of neurology resides. Because we as neurologists we love to localize, meaning that knowing the anatomy of the nervous system, we do a neurological exam to try to pinpoint exactly where the problem or the lesion is. It's sort of like in Houston when you say -- you zone in on a particular neighborhood like the Galleria or the Museum District, and you know what to find in that individual neighborhood. So as a neurologist, if you localize to the peripheral neurologic system, you have the individual nerves. They're connected to muscles, and then the nerves then run together into nerve plexuses. A plexus means web. So nerve plexus is a tangled nerve web, tangled web of nerves. And then that runs into individual nerve roots, which then feed into the spinal cord and then the brain. And so problems can exist at any of those levels. And knowing where the problem is helps you narrow down on the list of possibilities. And it's, you know, so we go through a process. There are more rare forms of peripheral neuropathy. So as you asked, there are plexopathies. There are disorders of neuromuscular junction. So the communication between the nerve and the muscle is impaired, so that a characteristic condition is myasthenia. So patients come in with motor weakness due to not a muscle problem or a nerve problem but in the communication between the two.Lisa Garvin: And Dr. Tremont, how you do work with Dr. Woodman to deal with these issues? It must be some sort of like team approach or how do you handle both the cancer and the morbidities?Dr. Ivo Tremont: Yeah. It is definitely a team approach. I, in the capacity of evaluate the patient initially and have a either confirmed diagnosis or have a clue of what is where the lesion is. But we definitely need Karin's skills to confirm it. She has a great knowledge in the area. And I would go to her for, you know, to present a challenging situation. What she thinks about that. How we better should treat that and ultimately to run the neurophysiology tasks that we do for patients with these conditions and that is the EMG. We call it EMG nerve conduction study, so which is a study that I will leave up to Karin to explain what is.Lisa Garvin: Yeah. And EMG stands for electromyopathy?Dr. Karin Woodman: That's Electromyography.Lisa Garvin: Okay.Dr. Karin Woodman: That's And it includes -- it's a two-part test that includes the EMG portion, which is done with a needle electrode inserted into the muscle so that we can record and analyze the electrical activity from the muscle. And then the other part is the nerve conduction study, which is stimulation of different nerves on the surface of the skin with a probe and recording the responses from those nerves. So the whole, the entire test is called EMG for short.Lisa Garvin: And so typically patients are referred to you with complaints. It's not like a preemptive thing where you're just doing it, you know what I mean?Dr. Karin Woodman: Typically not. So patients are usually referred to me for neurologic consultation first for rule out peripheral neuropathy or it seems to be like peripheral neuropathy but maybe a mimic. And we'll do a neurologic exam first in the clinic and then decide whether or not we need to go one step further and do an EMG test.Lisa Garvin: And there are common, probably known to the general public, drugs that are used for neuropathy treatment?Dr. Karin Woodman: Yes. So they're all, as Dr. Tremont mentioned. They're all symptomatic, meaning that we try to take care of the neuropathic pain with these drugs. And you know they're reasonably effective but many patients are left with residual symptoms that are acceptable with a little bit of numbness or tingling left over. And some patients need multiple combinations of medications as well.Lisa Garvin: So Dr. Tremont, are there any, you know, doing a lot of targeted therapies, drugs that are less toxic. Are there any drugs on the horizon that are trying to minimize neuropathic issues? Do you know what I mean? Ones that kind of target the receptors on the cancer cells and leave everything else alone.Dr. Ivo Tremont: Yeah. I think Karin could probably back me up about that, but there has been no -- there is some research on the nerve growth factors that if they're used in the appropriate setting for patients with a neuropathy, chemotherapy-induced neuropathy, it can affect the cores of the disease. And by that I mean they could be helpful. They can be effective. But this is only the beginning. I mean this peripheral neuropathies or -- we probably do a very good job at localizing, to make a localization diagnosis. But it is going to be tough to find the right treatment for there because we don't have anything specific against the neuropathy. It's something specific for the symptom, but not for the underlying process. All right.Lisa Garvin: And in closing, Dr. Woodman. What would you tell patients that are suffering through this? Words of encouragement or advice. What would you say?Dr. Karin Woodman: Well I'd say that always seek help when at the first sign of symptoms. If you're worried about a symptom, come on in and have it assessed. Try not to minimize your symptoms and tough it out. We have treatments for pain, for discomfort, just to make life better. And in the process, we can then try to look at the underlying cause. Neuropathy can be a cause or can be caused by not just the chemotherapy but by underlying conditions that are as yet not diagnosed. Patients may have early diabetes that they don't know about. They may have vitamin B12 deficiency or other nutritional deficiencies that can cause neuropathy. You know, I had a patient with a copper deficiency from a GI cancer causing her to not be able to walk. She was constantly falling. And so that diagnosis was made because she came in and kept being patient with us and allowed us to get her repleted with copper.Lisa Garvin: Because it seems like a lot of patients will say well, you know, my doctor's doing so much. I don't want to bother him about this little bitty thing.Dr. Karin Woodman: That's right. And my -- I really encourage patients to use all the resources available and come on in. If it's nothing to worry about, that's something that we can decide after we hear about the symptoms and take a look at everything.Lisa Garvin: Good advice. Dr. Woodman, thank you very much. Dr. Tremont, thank you very much.Dr. Ivo Tremont: Thank you Lisa.Lisa Garvin: If you have questions about anything you've heard today on Cancer Newsline, contact askMDAnderson at 1-877-MDA-6789 or online at ask. Thank you for listening to this episode of Cancer Newsline. Tune in for the next podcast.[Music] ................
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